29 



unite into one (fig. 145 A). In fig. 145 both the situation and the shape of the two bars is 

 represented. Probably the bars consist on the outside of cuticular matter, remaining after 

 decalcification, and staining i'aintly with carmine -, the inner part apjiears to me to have been 

 calcareous. The bars may also be hollow (cf. Thiele 8 fig. 47). Each bar is encircled by a 

 cubical epithelial layer, which is likewise surrounded by muscles : protractors and retractors. 

 Of a common epithelial layer surrounding ihcm nothing is perceptible. The glands belonging 

 to the penis-spicula are well developed. In fig. 1,^5/^ they are seen (violet) on the point of 

 opening into the covering of the penis-s]jicula ; their course is represented in figs. 136 — 140. 

 I''o- 139 shows a small vesicle ^^ connected with the precloacal organ by means of a little 

 tube (fig. 138); g and // unite into one large vesicle ^ + // (fig. 140), increasing in size more 

 proximally and dividing into lobes, as in fig. 142 it has been touched more than once. This 

 is undoubtedly the gland of the penis-spicula, described by Wiri.x and Thiele. Fig. 144 B 

 represents the structure of its wall : long strongly granular glandular cells, ciliated and with 

 oval nuclei {a) ; at different points the granules increase considerably in number and stain 

 intensely with carmine, the w-hole of the cells becoming dark-red (d). These granular cells are 

 especially found in vesicle ^. After g' and // have united this difference becomes evident, but 

 more proximally cells, more granular, are intermixed with cells less granular. Here and there 

 the cells open and the granules are discharged into the lumen of the gland. What kind of 

 organ may this be? Wirex and Thiele look upon the penis-spicula as being in some way 

 connected with the copulation, a view which to me too seems correct ; the function of o- 

 however cannot be made out. The spermatozoa from the precloacal organ might pass through 

 £■ and /i and then go to the penis-spicula; the name of the latter would be the more justifiable 

 on this account. Besides its secretory function the gland might also perform the office of 

 vesicula seminalis, the size and width of the gland favouring this view ; the secretion might 

 procure enveloping matter for the spermatozoa. This may to a certain extent also e.xplain the 

 fact of the spicula being hollow. Evidence against this view is the presence of numerous 

 spermatozoa in the precloacal organ, whereas in g they are entirely absent. Another inter- 

 pretation is this; in the gland a secretion is formed, partly convej-ed to the penis-spicula, partly 

 to the precloacal organ, which is confirmed by the presence of obviou.sly staining granules in 

 the precloacal organ and in tube g". 



Hemimenia is, no doubt, closely related to Neomenia. Yet I feel justified in considering 

 it another genus on account of the structure of the integument, which diffei's very considerably 

 from that of Neomenia. Neomenia belongs to the forms witli thick cuticle, pointed spicula and 

 ]>apillae, (group i pag. 21), Hemimenia to those with thin cuticle, flat imbricated spicula, 

 without papillae (group 2). It is therefore a transition-form and as such may be compared 

 with Paramenia. 



Cyclomenia nov. gen. 



Length-index 7. Shape of the body cylindrical, proximally bluntl)- truncated, distally 

 narrower and more pointed. Dorsal sense-organ present. Cuticle thick. Spicula pointed and in 



